Research Activities at TRC, Chennai...

The Tuberculosis Research Centre (TRC) is a leading research institution in the field of tuberculosis. The Centre is a permanent institute of the Indian Council of Medical Research (ICMR). It is globally recognized for its contributions in the field of tuberculosis. The strength of this institution lies in its ability to identify and carefully characterize various populations of patients with tuberculosis and follow them up for periods as long as 5-10 years. This has been possible due to the excellent teamwork that has been built up over the last 4 decades. The Centre has on its staff well-trained clinicians, epidemiologists, biotechnologists, social workers, health visitors and bio-statisticians to carry out these studies.
Controlled Clinical Trials
Operational Research
Training & Evaluation
Epidemiological Studies
Laboratory Studies

The Nobel Prize in Physiology or Medicine 2006

Last year's Nobel Laureates have discovered a fundamental mechanism for controlling the flow of genetic information. Our genome operates by sending instructions for the manufacture of proteins from DNA in the nucleus of the cell to the protein synthesizing machinery in the cytoplasm. These instructions are conveyed by messenger RNA (mRNA). In 1998, the American scientists Andrew Fire and Craig Mello published their discovery of a mechanism that can degrade mRNA from a specific gene. This mechanism, RNA interference, is activated when RNA molecules occur as double-stranded pairs in the cell. Double-stranded RNA activates biochemical machinery which degrades those mRNA molecules that carry a genetic code identical to that of the double-stranded RNA. When such mRNA molecules disappear, the corresponding gene is silenced and no protein of the encoded type is made.
RNA interference occurs in plants, animals, and humans. It is of great importance for the regulation of gene expression, participates in defense against viral infections, and keeps jumping genes under control. RNA interference is already being widely used in basic science as a method to study the function of genes and it may lead to novel therapies in the future.

Molecular Insights Into HIV Biology

According to the latest UN estimates, worldwide over 40 million people are infected with HIV, and the prevalence levels for this virus will continue to rise globally. Historically, vaccines have proven to be the most effective weapon in our fight against infectious diseases such as small pox, polio, measles, and yellow fever. HIV vaccines are our best hope to end the HIV pandemic.

Bringing the global HIV epidemic under control will require more effective approaches to prevent the spread of the retrovirus, as well as broader use of existing and future antiretroviral drugs. These interventions must be applicable in the developing world, where HIV has the most severe impact. Understanding the dynamic interplay of HIV with its cellular host provides the biological basis for controlling the epidemic. This chapter reviews current understanding of the HIV life cycle, with particular attention to the interactions between viral proteins and cellular machinery, and highlights promising future points of attack.

CELL CYCLE:Order from Destruction

Cyclin E and its kinase partner CDK2 are essential for initiating duplication of the genome during S phase of the cell cycle. But how is cyclin E itself regulated? In a comprehensive Perspective, Bartek and Lukas describe new findings in this issue and elsewhere that identify an F-box protein called Fbw7/hCdc4/Ago as the controller of cyclin E degradation. Intriguingly, mutations in this F-box protein are associated with some forms of breast and ovarian cancer.

Vacancies at Vimta labs

Hyderabad based Vimta labs is a multi-disciplinary Contract Research and Testing Organisation.It is to expand its presence to Newdelhi and Noida and requires applications for the follwing posts for its extension centres at Noida.

Recognition of the Codon-Anticodon Helix by Ribosomal RNA

Translational fidelity is established by ribosomal recognition of the codon-anticodon interaction within the aminoacyl-transfer RNA (tRNA) site (A site) of the ribosome. Experiments are presented that reveal possible contacts between 16S ribosomal RNA and the codon-anticodon complex. N1 methylation of adenine at position 1492 (A1492) and A1493 interfered with A-site tRNA binding. Mutation of A1492 and A1493 to guanine or cytosine also impaired A-site tRNA binding. The deleterious effects of A1492G or A1493G (or both) mutations were compensated by 2'fluorine substitutions in the mRNA codon. The results suggest that the ribosome recognizes the codon-anticodon complex by adenine contacts to the messenger RNA backbone and provide a mechanism for molecular discrimination of correct versus incorrect codon-anticodon pairs.

Tiny RNA World Discovered...

Two small temporal RNAs (stRNAs), let-7 and lin-4, play an important role in the development of the nematode Caenorhabditis elegans. Let-7 is also highly conserved throughout bilateral animals, including Drosophila and humans. Are there other small regulatory RNAs? Three reports by Lagos-Quintana et al., Lau et al., and Lee et al. indicate that there are a very large number (>60) of these tiny ~22-nucleotide microRNAs (miRNAs)and that they have molecular characteristics similar to the two known stRNAs. The miRNAs are developmentally and tissue-specifically expressed and are conserved between different organisms. Some of the RNAs are organized in an operon-like fashion and may be processed from a single precursor. In a Perspective, Ruvkun calls the RNAs the "biological equivalent of dark matter" and suggests that they may provide a potent means for regulating gene expression.

Protein Composition of Catalytically Active Human Telomerase from Immortal Cells

Telomerase is a ribonucleoprotein enzyme complex that adds 5'-TTAGGG-3' repeats onto the ends of human chromosomes, providing a telomere maintenance mechanism for 90% of human cancers. We have purified human telomerase 108-fold, with the final elution dependent on the enzyme's ability to catalyze nucleotide addition onto a DNA oligonucleotide of telomeric sequence, thereby providing specificity for catalytically active telomerase. Mass spectrometric sequencing of the protein components and molecular size determination indicated an enzyme composition of two molecules each of telomerase reverse transcriptase, telomerase RNA, and dyskerin.